Colombia, which ranks fourth in the total number of HIV reported cases in Latin America, implemented a law in 993 to guarantee basic medical care for HIV-infected people. In 1997, provision of antiretrovirals was nandated. Health Services Providers have designed different Delivery Health Care Models to provide ;overage for HIV infected patients. The proposed health research initiative, by a new foreign investigator, will evaluate for the first time, the utilization and cost implications of different representative delivery health care models in Bogota, Colombia. Assessment of cost-effectiveness is vital not only in the area of treatment but also in regard to the use of diagnostics, provision of care, support services, and prevention strategies and programs. A multi-step evaluation of three main Delivery Health Care Models (Open Pre-Paid, EPS, Social Security) available in Bogota, is proposed. First, information will be obtained to determine the type of specific services available for each delivery model. Second, data obtained from 450 HIV-infected individuals (150/model) will be systematically collected and prepared for statistical analysis. In the third phase, models will be compared in terms of health services utilization, costs, cost-effectiveness and which health care model best accomplishes delivery and sustains adherence to HAART. Evaluation of service utilization will consider the impact on disease progression, as indicated by CD4 cell count and viral burden. Outcomes will be aggregated to determine the level of total services required for adequate care for each delivery model. In the proposed research application, the Miami Fogarty Group will provide appropriate resources and guidance to Dr. Burbano, the new foreign investigator, for the implementation of the study, including expertise in health care services and evaluation, research methodology, quality control, data management and data analyses. It is expected that the conduct of this study will advance Dr. Burbano's ability to become a scientific leader in health research. Findings from this project should provide necessary information to help determine the optimal use of HIV delivery services and help develop public health strategies to achieve equity in health services, for HIV infected people in Colombia, and possibly other countries in Latin America.